Deep sedation with propofol by pediatric intensive care physician during magnetic resonance imaging procedures: a prospective experience.
E Gomez, C Lopez-Menchero, D Lozano, P Oyagüez, C Zabaleta
deep sedation, infants and children, magnetic resonance imaging mri, procedural sedation, propofol
E Gomez, C Lopez-Menchero, D Lozano, P Oyagüez, C Zabaleta. Deep sedation with propofol by pediatric intensive care physician during magnetic resonance imaging procedures: a prospective experience.. The Internet Journal of Pediatrics and Neonatology. 2009 Volume 12 Number 1.
Magnetic resonance imaging (MRI) is now considered as the imaging method of choice for the diagnosis of a wide number of congenital and acquired pediatric diseases. This examination requires patients to stay still for a variable length of time of up to an hour in a closed, claustrophobic and noisy environment; hence the need for sedation in children is very common to ensure that images are of diagnostic quality. The demand for sedation and anesthetic procedures in general hospitals often exceeds the availability of trained anesthesia personnel which means a delay of imaging procedures especially in children
Material And Methods
All children between 6 months and 14 years undergoing MR imaging who were referred for deep sedation in the pediatric intensive care unit of the Hospital General de Ciudad Real (Spain) were prospectively included in this study during an 18-month period (October 2006 to march 2008). Children with ASA physical status > III, egg or soy allergy or intubated
A preoperative assessment was performed on all children and written informed consent was obtained from parents. During this evaluation a medical history was taken and a physical examination was performed. Additional data recorded included age, gender, weight and indication for MRI. The children fasted from solids for 6 h and from clear liquids for 3 h prior to sedation on the day of the procedure. If the child did not meet strict fasting criteria or presented with symptoms or history consistent with upper respiratory tract infection, the procedure was rescheduled. Before sedation, an intravenous access was established and intravenous hydration was started if needed. The complete sedation procedure took place in the MRI room where oxygen, suction, and pediatric resuscitation equipment were available. At least one parent was with the child during the induction of sedation. The induction consisted of two doses of Propofol injected with a syringe pump (Alaris GH Cardinal Health Inc) over 3 minutes each one. The first dose was 2 mg/kg and the second 1 mg/kg with a total induction dose of 3 mg/kg over 6 minutes. After the induction, a continuous infusion via a syringe pump was started at a rate chosen by the pediatrician of between 1, 5 or 10 mg/kg/h to maintain deep sedation. Our goal was to achieve a level > 5 on the Ramsay scale
A total of 41 patients between 6 months and 15 years were referred to pediatric intensive care unit for deep sedation during MRI procedures. Three patients lost the intravenous line before propofol induction dose had been completed and these children were excluded, although the MRI procedure could be finished successfully without infusion of more doses of propofol or other sedative agent. One patient had egg allergy and other two did not need sedation during the study. Finally 35 patients underwent 36 MRI studies. The mean age was 4.4 ± 3.8 years (range 6 months-13.4 years). The mean weight was 18.6 ± 13.7 kg (range 6.3 – 53 kg). There were 22 boys and 13 girls. Most were healthy; thirty two (91.4%) were classified as ASA class I or II, and three (8.6%) as ASA III. The MRI studies performed are listed in Table I. Original diagnoses are listed in table II.
The mean duration of procedure was 30.3 ± 13.6 minutes (range 15-70 minutes). The mean dose of propofol was 5.31 ± 2.2 mg/kg. The median infusion rate after induction was 4.99 ± 3.4 mg/kg/h. The maintenance rate was started at 1 mg/kg/h, 5 mg/kg/h and 10 mg/kg/h in 6, 17 and 13 cases, respectively. The initial infusion rate was modified once during procedure in 17 cases, and in all cases infusion rate was decreased. Titration was performed in thirteen procedures where the initial rate was 5 mg/kg/h and in four who had 10 mg/kg/h as initial rate. Deep sedation with Ramsay score of 6 was reached in all cases. Propofol infusion resulted in a decrease in heart rate and respiratory rate in all children. There was no respiratory depression or oxygen desaturation in any child. All MRI procedures could be finished successfully. In one case the MRI sequence was stopped when the propofol loaded in syringe pump was finished. The child moved but he did not recover consciousness and the procedure could be completed satisfactory after restarting propofol infusion at the previous rate, 10 mg/kg/h. All the patients could be transferred to the ward after the end of the propofol Infusion. All patients started oral feeding in first hour after MRI and all outpatients were ready to discharge in the following hour. None of the patients experienced any episode of postoperative nausea and vomiting or any other side effect up to discharge.
Over the past decade, propofol based sedation has been used increasingly for procedures outside the operating room setting
This prospective observational report describes a protocol for using propofol for deep sedation in children undergoing MRI procedures and it confirms that propofol can be used safely and effectively by intensive care pediatricians in the MRI room. The main difference with other protocols was the induction phase. Our protocol offers a predictable induction and it suggests that if induction dose is infused slowly (over six minutes in our case),, the incidence of apnea can be reduced. As expected, sedation with propofol offered an easy titration, low failure rate and a rapid recovery without gastrointestinal adverse effects.
The authors thank the Department of Pediatrics and Radiology and the pediatric nurse team of Ciudad Real General Hospital for their cooperation in this project.